The present invention relates to bobbins or spools for textile yarns or the like. More particularly, the invention relates to improvements in bobbins or spools which perferably consist, at least in part, of synthetic thermoplastic material and constitute hollow cones or cylinders. Such bobbins are used to support rolls consisting of textile yarns or other filamentary material during wet- and/or heat-treatment in a dyeing plant or the like.
It is desirable that the bobbins should be capable of elastic deformation in the axial direction thereof and that the bobbins should also be capable of undergoing elastic deformation in the radial direction thereof, at least in the course of heat-treatment of filamentary material. At the same time, the configuration of the bobbins, especially their inner diameter, should undergo a negligible change or should remain constant.
Presently known bobbins or spools which are used to store rolls consisting of coiled textile yarns or the like during wet- and/or heat-treatment are usually smooth-surfaced hollow cylinders or cones which are perforated or constitute a lattice-work with a large number of apertures for the circulation of a fluid treating medium. Reference may be had to German Auslegeschrift No. 1,635,118. A simple bobbin which is merely provided with perforations is often incapable of exhibiting satisfactory deformability in the course of wet- and/or heat-treatment of yarns. On the other hand, a bobbin whose body is a latticework is incapable of withstanding appreciable radial stresses without permanent deformation and/or excessive change in its configuration.
Another serious drawback of presently known perforated or sieve-like bobbins is that their manufacturing cost is too high and that their versatility is unsatisfactory. Thus, the construction of a large-diameter bobbin is quite different from that of a smaller-diameter bobbin. This, too, contributes to the manufacturing cost and creates problems in connection with storage of different types of bobbins.